Definition
This idiom suggests that a dishonest person is best suited to recognize or apprehend another dishonest individual.
以贼捕贼
The police, in their effort to catch the scammer, collaborated with someone who had a prior criminal record.
警方为了抓住诈骗犯，与一位有犯罪前科的人合作。
He would never have known what they were plotting if he hadn't done the same thing himself before.
要不是他以前做过同样的事，他永远不知道他们在策划什么。
They hired a former hacker to track down and catch the cybercriminals.
他们雇用了一位前黑客来追踪并抓获网络犯罪分子。